Hello Med, "I have to" is correct. "I got to" is a slang contraction of "I have got to". "I have to" is better English, and you should use that. It means you must do a certain thing. examples: I have to wear a coat because the weather is very cold. The show starts at 8pm so we have to be there by 7.45. I have to buy a sandwich because I am hungry.

Hello Med, this question was asked very recently: see the answers here https://www.italki.com/question/424736